Integrate interpolation support from XIOS

[TomMelt]

Integrate interpolation support from XIOS

Fixes #979

Task List

• Linked an issue above that captures the requirements of this PR
• Defined the tests that specify a complete and functioning change
• Implemented the source code change that satisfies the tests
• Commented all code so that it can be understood without additional context
• No new warnings are generated or they are mentioned below
• The documentation has been updated (or an issue has been created to do so)
• Relevant labels (e.g., enhancement, bug) have been applied to this PR
• This change conforms to the conventions described in the README

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Change Description

This PR exposes the interpolation functionality of XIOS into nextsim.

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Test Description

• XiosForcingInterpolation_test.cpp tests XIOS interpolation from a low resolution grid (from file) to the higher resolution grid (in the test)

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Documentation Impact

To be completed

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Other Details

N/A